Boston: Step counting apps could be driving people to chase over-ambitious goals, a leading computer scientist has claimed. Dr Greg Hager, from Johns Hopkins University in the US, said “very few” of the estimated 165,000 available healthcare apps are based on scientific evidence. He is especially critical of apps and devices that set users a target of 10,000 steps. Speaking at the annual meeting of the American Association for the Advancement of Science (AAAS) in Boston, he said: “Some of you might wear Fitbits or something equivalent, and I bet every now and then it gives you that cool little message ‘You did 10,000 steps today’. “But why is 10,000 steps important? What’s big about 10,000? “Turns out in 1960 in Japan they figured out that the average Japanese man, when he walked 10,000 steps a day, burned something like 3,000 calories and that are what they thought the average person should consume. So they picked 10,000 steps as a number. “But is that the right number for any of you in this room? Who knows?” Dr Hager said that a survey of several hundred mental health apps for coaching and diagnosis found only five that could be linked to an evidence base. But none of those were available to the public – they were all research tools. He added: “I think apps could definitely be doing more harm than good. I am sure that these apps are causing problems. “Without any scientific evidence base, how do you know that any of these apps are good for you? They may even be harmful.”